CONTENTS
1.0 INTRODUCTION
2.0 EXISTING INFRASTRUCTURE
2.1 UTILITY SEARCHES
2.2 VERIFYING RECORD INFORMATION
2.3 INITIAL ENQUIRY UTILITY CONTACT
INDIVIDUAL REQUIREMENTS
2.3.1 EDF ENERGY
2.3.2 NATIONAL GRID
2.3.3 BRITISH TELECOM (OPENREACH)
2.3.4 THAMES WATER (POTABLE WATER)
2.3.5 THAMES WATER (DRAINAGE)
DETAILS
AND
3.0 NEW CONNECTIONS
3.1 ELECTRICAL SERVICE
3.1.1 EDF ENERGY REQUIREMENTS
3.1.2 SPACE PLANNING LOW VOLTAGE CONNECTIONS
3.1.3 HIGH VOLTAGE SUPPLY AND LV / HV SUBSTATIONS
3.2 BRITISH TELECOM
3.2.1 TYPICAL CONNECTION ARRANGEMENTS
3.3 GAS (FULCRUM)
3.3.1 ESTABLISHING AVAILABILITY OF GAS CAPACITY AT
THE PROPOSED DEVELOPMENT BOUNDARY
3.3.2 METER LOCATION AND SPACE ALLOWANCES
3.3.3 TYPICAL DETAILS
3.4 POTABLE WATER (THAMES WATER)
3.4.1 ESTABLISHING AVAILABILITY OF WATER CAPACITY AT
THE PROPOSED DEVELOPMENT BOUNDARY
3.4.2 THE NEW WATER SUPPLY
3.5 DRAINAGE (THAMES WATER)
3.6 ACCOMMODATING FUTURE SERVICES
3.6.1 CONNECTING TO A DECENTRALISED ENERGY
SCHEME
3.6.2 DECENTRALISED ENERGY SCHEME SUBSTATIONS
4.0 COORDINATION
4.1 BEST PRACTICE
4.2 TYPICAL BUILDING CONNECTION ARRANGEMENT
4.3 INCOMING UTILITY GOOD PRACTICE PLANNING
4.3.1 STREETWORKS COORINDATION
4.3.2 CITY OF LONDON CONSIDERATE CONTRACTORS
4.4 BUILDING INTERNAL / BASEMENT UTILITY SERVICE
LAYOUT
4.5 SERVICE ENTRY DETAILS
5.0 REFERENCE DOCUMENTATION
6.0 PLANNING CONSIDERATIONS
1.0 INTRODUCTION
As within any major city, the roads and pavements of the
City of London are densely populated by many utility
operators’ distribution cabling, pipework, plant and
equipment. The City offers excellent opportunities in
terms of service availability, capacity and security,
however early planning and coordination is paramount in
ensuring that services to new developments can be
accommodated efficiently.
This guidance document has been produced on behalf of
the City of London to assist developers, consultants and
construction industry professionals in planning utility
investigations, diversions and new connections to City
development sites.
This document includes best practice advice provided by
individual Utility Companies and should be read in
conjunction
with
other
relevant
statutory
regulations/guidelines.
This document was drawn up in conjunction with the
major utility infrastructure asset owners within the City of
London, namely;
ƒ
EDF Energy
Electrical infrastructure
ƒ
ƒ
ƒ
Gas infrastructure
ƒ
ƒ
National Grid &
United Utilities
Fulcrum Infrastructure
Services
Thames Water
British Telecom
ƒ
EON / City Gen
New gas connections
Potable water and drainage
Telecommunications
Owners of existing
heating system.
district
Whilst the document provides early scheme guidance,
individuals should ensure that Utility Companies are
consulted directly with respect to the details of each new
development.
The document is structured in three principle sections;
ƒ
ƒ
ƒ
Existing infrastructure
New supplies
Co-ordination
2.0 EXISTING INFRASTRUCTURE
Prior to commencing any development the impact upon
pre-existent utility infrastructure should be identified. This
is imperative for a number of reasons, but primarily to
protect service provider installations.
Often, within a utility company, different departments
manage existing infrastructure to those planning new,
hence this document is split accordingly.
Whilst most utility installations are within public footways
and highways, some have had to cross private land and
in such instances a legal access entitlement known as
‘Wayleave’ will be in place. This provides the service
provider with ‘unfettered’ access rights to his plant when
on a private property. These legal titles are normally held
by the private land owner and would not normally
become evident through the normal routes of enquiry,
however the existence of a Wayleave agreement can
have a significant impact on a development. Necessary
checks should be made and where a wayleave is
identified the asset owner should be contacted at the
earliest opportunity to discuss the impact of your
development.
In performing the searches it is as important to identify
not only those services which impact the site directly, but
also those running adjacent development sites.
Restrictions exist regarding the proximity of new
structures and construction activity adjacent pre-existent
services which might need to be addressed by a
developer.
2.1 UTILITY SEARCHES
There a several ways of identifying existing utility
installations on, and around, a development site.
Traditionally, enquiries are made directly to each known
utility company via their records and mapping
departments. A list of the appropriate departments are
provided herein for each service provider.
With de-regulation and the utilities market becoming
broader commercially, more service providers operate
throughout the City than ever before, the records for who
will also be required. Operators often change ownership,
particularly in the telecommunications market, and plant
physically identified on site may no longer be in the
ownership of the operator as labelled.
To this end, a number of businesses now provide a full
search enquiry service and will perform the sometimes
onerous task of identifying local operators and retrieving
records. Such companies are detailed below;
ƒ
ƒ
Centre Maps – Malcolm Hughes Ltd
Groundwise
2.2 VERIFYING RECORD INFORMATION
It is important to note that record drawings are mostly not
to scale and are a representation of installations only.
Precise locations for plant and equipment should only be
verified visually on site. Ground penetrating radar and ‘cat’
scan surveys can be of assistance in less densely populated
locations.
Upon receipt of the record information the development site
should be referenced against the existing installations, with
any potential diversions, pinch points and development
restrictions identified.
It is then recommended that trial digs are performed by
approved contractors to precisely identify line and location of
services at critical points. It is also worth doing the same at
the proposed new service connection points to coordinate
the provision of new chambers and the like.
Note that service providers have minimum depth and
clearance requirements for their installations. As such the
‘third dimension’ should also be considered in these
investigations, such that the impact of any surface level
changes on infrastructure can also be assessed.
If infrastructure is found close or crossing the development a
developer will need to agree with the asset owner the scope
of diversions, costs and program prior to construction work
commencing. In most cases the developer is liable for all
diversion costs.
Generally, the asset owner will make these diversions
however, some of the work may be contestable and can be
undertaken by a licensed independent connections provider
(ICP) within the Distribution networks operator (DNO’s)
region. For reference, a licenced Independent Distribution
networks operator can run as an independent network within
the DNO region.
2.3 INITIAL ENQUIRY UTILITY CONTACT DETAILS AND
INDIVIDUAL REQUIREMENTS
The contacts below represent the five key asset owners
within the City area. It should be noted there are a number of
other providers likely to have infrastructure and these should
be considered when performing a search.
Amongst these are a large number of telecom providers and
the City of London offer an online search facility to ascertain
providers within the vicinity of your development.
2.3.1 EDF ENERGY
Records
EDF offers record search facility to enquiries made by
developers their team and builders – a charge is made for
this service.
Plan Provision
EDF Energy Networks
Fore Hamlet
Ipswich
Suffolk
IP3 8AQ
Tel 08701 963772
2.0 EXISTING INFRASTRUCTURE
2.3.2 NATIONAL GRID (GAS)
Records
National Grid
Plant protection
Block 1 Floor 2
Brick Kiln
Hinkley
LE10 0NA
Tel 0800 688 588
[email protected]
2.3.3 BRITISH TELECOM (OPENREACH)
For way leave negotiations contact BT on 0800 581 525
option 4 or email [email protected]
2.3.4 THAMES WATER (POTABLE WATER)
Thames Water owns, operates and maintains the majority of
water services within the City of London. The water industry
has a limited competitive market through inset appointments
or water supply licensing hence other service providers’
infrastructure could be expected within the City of London.
For the purpose of this document only Thames water
services and connections are considered.
Records
Records
A BT infrastructure record enquiry can be made either via
their maps by email service (MBE) available by
registering via www.openreach.co.uk
Thames Water Property insight department:
Or contacting the BT new sites office covering the city of
London who are at:
http://www.twsearches.co.uk/
Telephone 0118 925 1504
Romford
0800 731 7346
[email protected]
Very large schemes and more detailed paper copies are
available from BT’s National notice handling centre:
National Notice Handling Centre
PP 3WW18, Telecom House,
Trinity Street,
Hanley,
Stoke-on-Trent,
ST1 5ND.
Freephone: 0800 800865
Freephone: 0800 800 865
Thames Water Property Insight
PO Box 3189
Slough
SL1 4WW
Diversions
If it is established that their infrastructure may require input
from Thames Water contact Thames Water Developer
Services, via the following contact details:
Developer Services helpdesk on 0845 850 2777.
Thames Water
1 Kew Bridge
Brentford
Middlesex
TW8 0EF
[email protected]
Diversions
BT also offers a free ‘dial before you dig’ service and will
come to site with 24hours notice to locate and mark out
the location of their service
0800 917 3993
www.dialbeforeyoudig.com
[email protected]
Liaise with the new sites team from then onwards who
will work with the developer’s team in relocating their
services around the scheme.
If a service that does not feed the development site
encroaches on the site boundary a wayleave will be
required.
2.3.5 THAMES WATER (DRAINAIGE)
The adopted drainage system within the City of London is
owned, operated and maintained by Thames water.
Connections to main sewers are owned by either the City of
London or the local development they serve.
Other connections to the main drainage system are often
owned by the development they serve or are owned by the
City of London mostly where they serve highway drainage
systems.
For the purpose of this document Thames water services
and connections are considered.
2.0 EXISTING INFRASTRUCTURE
Diverting an existing sewer or building over.
If the location of a public sewer prevents land
development or property extension, it may be possible to
divert the sewer(s) onsite via an adoption agreement
(Section 104/116). However, Thames Water will divert
strategic sewers, if practical, on a chargeable basis
(Section 185).
Should the location of a public sewer prevent land
development or a property extension, it may be possible
to build over the sewer (Section 18 Building Act 1984).
This will be subject to Thames Water approval.
For all sewer classes, except class one domestic, survey
will be required. This is usually undertaken by closed
circuit television (CCTV). There are standard fees for this
service based upon the size of sewer affected.
Specific requirements for diversion should be discussed
with Thames water.
Records
Thames Water Property insight department:
http://www.twsearches.co.uk/
Telephone 0118 925 1504
Thames Water Property Insight
PO Box 3189
Slough
SL1 4WW
Diversions
Developer Services helpdesk on 0845 850 2777.
Thames Water
1 Kew Bridge
Brentford
Middlesex
TW8 0EF
[email protected]
2.0 EXISTING INFRASTRUCTURE
2.1 EXAMPLE UTILITY DIVERSION PROCESS
Define development
boundaries, adjacent public
and private areas.
Contact utilities to obtain
record information
A list is available from the local
council or alternatively you can use a
service provider such as Centre Maps
Identify which utilities are
likely to be impacted,
contact each utility with
details of the development
at the earliest opportunity.
You may also wish to request an
indicative cost for the diversion. A
payment may be required for this.
Determine co-ordinated
diversion strategy including
program and what civil
works are to be carried out
by the contractor
Appoint each asset owner
for formal cost and
agreement to your program
Obtain necessary street
works licences.
Make necessary payments
in advance or works
Start works
Consider co-ordinating the diversion
strategy with the new service
connections.
3.0 NEW CONNECTIONS
3.1 ELECTRICAL SERVICE
Depending upon the size of the development and the
condition of the local infrastructure, reinforcements to the
pre-existent infrastructure may be required to support the
additional load.
Invariably, reinforcement works will be at the developers
cost. It is important, therefore, to ensure that loading
assessments are as accurate as possible to ensure
reinforcement costs are not attracted unnecessarily. As
such it is recommended that loading analysis be performed
by competent and experienced persons.
3.1.2 SPACE PLANNING - LOW VOLTAGE
CONNECTIONS
Please note: diagrams provided are for general
guide only and the correct details should always be
obtained from your proposed DNO.
Low voltage network connections typically range from
100A up to 400Amps (400v).
Suitable access and space should be made for the
following equipment depending on connection size.
Competitive bids for network installation, adoption and
operation can also be sought in particular instances.
Professional counsel is recommended where developers
are considering this route.
Cable access is usually via provision of cable ducts
from the public footway, duct and cable entries should
be sealed against water and gas ingress under
pressure. The cut out location should ideally be above
ground and accessible from the street level.
3.1.1 EDF ENERGY REQUIREMENTS
The cut outs should be kept clear and an access route
for maintenance should be maintained.
Other considerations at this stage should include:
Connections up to 100Amp 3Phase
ƒ
Secondary supply requirements.
Alternative grid
network supply for standby or life safety equipment (as
opposed to local generator supply)
ƒ
Onsite generation proposals, such as Combine Heat
and Power (CHP)
ƒ
Most appropriate supply voltage (400V or 11kV)
300
Cut
out
back
board
500
Minimum
500mm
Note that utility electrical infrastructure plant typically has
up to 9 months lead in from the point of order. Similarly,
offsite, ‘upstream’ reinforcements to the electrical network
can take up to 18 months to procure and implement having
to work around planed networks outages, highways
operational restrictions and the like.
Typical 100amp
cut out
New Connections
Connections up to 400Amp 3 Phase
EDF Energy Networks,
Projects Gateway,
Metropolitan House,
Darkes Lane,
Potters Bar,
Herts,
EN6 1AG
Tel : 08701 964 599
Email :[email protected]
Further information and new supply application forms are
available from EDF’s web site www.edfenergy.com
ELECTRICAL
500
Standard
Meter
Panel
Back
Board
540
400A
CUT
670
Minimum
500mm
3.0 NEW CONNECTIONS
3.1.3
High Voltage supply and LV / HV substations
The optimum and preferred location for a 11kV substation
is a room facing onto the street at ground floor level. This
affords the best ventilation, access and reduces risk of
flooding.
The developers main LV switchboard room should be
adjacent to the substation to keep service cables as
short as possible.
Please note: diagrams provided are for general
guide only and the correct details should always be
obtained from your proposed DNO.
The developer is urged to engage the proposed provider
on access, leasing and other legal issues early on as these
can considerable time to resolve and power will not be
switched on until all area resolved.
4630mm
Secure louvre to provide 1m
fee area to outside
Earth
2
3500mm
2500mm
height room
Typical
transformer
4700 kgs.
Trench details to include
suitable cover plate / grilles
1050mm
deep
Earth
1050mm
deep trench
300mm
deep trench
Duct entry and exits
11kV utility owned intake and transformer 1MVA
with Low Voltage distribution.
For full details refer to EDF detail NP17
ELECTRICAL
3.0 NEW CONNECTIONS
Most utility operators do recognise that a ground floor
location may not be possible to achieve due to listed
facades etc. and can offer a below ground transformer
solution considered on a individual site specific basis. The
developer should be carefully considered this against a
number of factors, including:
•
•
•
•
•
•
•
Site based flood assessment, making use of the
City of London’s strategic flood risk assessment
available through their web site (web link provided
in the references)
Does the transformer serve only the building it is
in?
Provision of utility unfettered 24hour access
Low loader access for transformer replacement.
Natural ventilation requirements.
Fire risk
HV Cabling routes and ongoing Low Voltage
cabling lengths
Alternative / Essential supply intake position
Please note diagrams provided are for general
guide only and the correct details should always be
obtained from your proposed DNO.
Access
hatch with
suitable
lifting beam
above
4500mm
Earth
4200mm
Earth
300mm deep
trench
High and low level
ventilation to outside approx
1m2 each
A
A
External louvers 150mm
above street level
External street
level
2775mm
min
500mm
SECTION A - A
ELECTRICAL
11kV utility owned transformer installed below
ground.
For full details refer to EDF detail NP12
3.0 NEW CONNECTIONS
11kV utility ring main unit only below ground
Where the developer wishes to purchase electrical energy
at 11kV meaning they own and operate the transformer.
The developers’ designer will be responsible for the
transformer room design. Allowance will need to be made
for the utilities ring main unit only.
Please note diagrams provided are for general
guide only and the correct details should always be
obtained from your proposed DNO.
Access
hatch with
suitable
lifting
beam
3272mm
High and low
level air brick
4060mm
Ringmain
unit
Earth
3.1.4 132kV Utility owned Transformer
It should be note that the installation of a 132kV
transformer on or under a building is complex. If the
development requires a connection at this voltage level
the DNO should be involved to determine space and
access requirements.
ELECTRICAL
Earth
3.0 NEW CONNECTIONS
3.2 BRITISH TELECOM
Depending upon the size of the development and the
condition of the local infrastructure, reinforcements to the
pre-existent infrastructure may be required to support the
additional capacity.
3.2.1 TYPICAL CONNECTION ARRANGEMENTS
Typical single occupancy retail or domestic connection (up
to 20 lines)
BT typically provide reinforcement works as part of the
connection charge. Estimation of the number of lines
and data services required should be provided early
within the scheme procurement to establish necessary off
site reinforcement.
Competitive bids for network installation, adoption and
operation can also be sought in particular instances.
Professional counsel is recommended where developers
are considering this route.
Of the many other telecom operators available within the
city most will accept infrastructure designed and installed
to the BT standards. Hence to permit further diversity
these allowances should be duplicated.
Consideration could also be given to use of the City of
London’s own telecom duct infrastructure that can permit
interconnections between buildings and other
infrastructure.
New connections
In the first instance for a new scheme, if using BT, is to
contact their local new sites team with the city of London
being covered by their Romford team.
Romford
0800 731 7346
[email protected]
BT have produced a useful document called their ‘Build
Pack’ which contains all necessary details for arranging
and making allowance for new service connections (refer
to link provided in the reference section for a copy).
The below information is given as a guidance for early
planning of a scheme
Each development will be unique and specifics should be
discussed with the new sites team the details provided
here are typical arrangements to aid an early planning.
BRITISH TELECOM
Typical office or multiple occupancy tenancy building
>20lines including blow fiber.
3.0 NEW CONNECTIONS
Typical local chamber construction
For future safe excavation and to avoid interference with
copper networks BT require a 600mm separation from
other services, where this cannot be achieved BT should
be consulted directly to review available alternatives.
BRITISH TELECOM
3.0 NEW CONNECTIONS
3.3 GAS (FULCRUM)
3.3.2 Meter location and space allowances
Depending upon the size of the development and the
condition of the local infrastructure, reinforcements to the
pre-existent infrastructure may be required to support the
additional demand.
The ideal location for a meter should be in a purpose built
external meter box with suitable ventilation. Also considered
are specifically constructed rooms to the outside of a
building or internal to the building but on an external wall for
natural ventilation.
Invariably, reinforcement works will be at the developers
cost. It is important, therefore, to ensure that gas
demand assessments are as accurate as possible to
ensure reinforcement costs and infrastructure charges
are not attracted unnecessarily.
As such it is
recommended that loading analysis be performed by
competent and experienced persons.
Internal termination points for single supplies should be
<=2m from entry into the building, ideally on the inside face
of the external wall, with a pressure relief element
incorporated. Ventilation should be 2% of internal floor area
or notional equivalent – split between high and low level.
The meter must not be on a means of escape route.
Competitive bids for network installation, adoption and
operation can also be sought in particular instances.
Professional counsel is recommended where developers
are considering this route.
3.3.1 Establishing availability of gas capacity at the
proposed development boundary
Understanding the impact that the new development will
have on the existing network will enable the developer’s
team to plan and budget for any enhancements required.
The Primary gas distribution network in London is owned
and operated by National Grid Gas which is regulated by
ofgem. Connections to new developments can be via a
number of options:
i.
via a licensed Utility Infrastructure Provider (details
of whom are available on Ofgem’s website
www.ofgem.gov.uk), or
ii.
through a gas supplier, or
iii.
via National grids connections department carried
out by Fulcrum gas services limited if over
73,200kWh per annum.
Physical meter dimensions
Once the building gas demand has been established the
meter size can be determined. The table below identifies
typical sizes up to 160m3/h.
Meter
Model
Capacity
m³/h
Depth
mm
Width
mm
Height
mm
Weight
kg
U16
U25
U40
U65
U100
U160
16
25
40
65
100
160
346
308
381
385
552
552
343
406
553
614
775
775
283
415
496
545
630
660
9.5
16.4
28
41.8
70
75
Larger supplies are often metered using turbine flow meters,
details of which are available from the developers’ chosen
gas supplier.
Ventilation
Example Utility infrastructure enquiries for a new
development:
Fulcrum Infrastructure Services Limited
Customer Care
Carr House
Greasbrough Road
Rotherham
South Yorkshire
S61 4QQ
Tel: 0845 641 3010
Email : [email protected]
www.fulcrum.co.uk
GAS
The meter compartment should have a natural means of
outside ventilation. Louvred ventilators, or equivalent, should
be distributed evenly across external walls at both high and
low levels – as a guide the total ventilation area should at
least be 3% of the floor.
Low level ventilators should be placed at a maximum height
above floor level of 150mm.
High level ventilators should be positioned at a height from
the
ceiling
of
10%
of
the
height
of
the
compartment/room/housing.
Further details on the location and enclosure are available
from the developments chosen shipper.
3.0 NEW CONNECTIONS
3.3.3 Typical details
Below is an external gas meter housing and incoming
gas pipe detail.
For guidance on installing a meter inside a building or in
basement locations guidance should be sought from the
chosen gas supplier.
Please note: diagrams provided are for a general guide
only and each installation will differ for the correct
details should always be obtained from your proposed
shipper.
Detail taken from E-on energy services guidance document
GAS
3.0 NEW CONNECTIONS
3.4 POTABLE WATER (THAMES WATER)
Depending upon the size of the development and the
condition of the local infrastructure, reinforcements to
the pre-existent infrastructure may be required to
support the additional demand.
Invariably, reinforcement works will be at the
developers’ cost. It is important, therefore, to ensure
that water demand assessments are as accurate as
possible to ensure reinforcement costs and
infrastructure charges are not attracted unnecessarily.
As such it is recommended that loading analysis be
performed by competent and experienced persons.
Competitive bids for network installation, adoption and
operation can also be sought in particular instances.
Professional counsel is recommended where
developers are considering this route.
Construction site temporary water supply
If the existing supply is already metered, Thames Water
must be notified before work commences. Details of the
site address and the meter number will be required
Where an existing unmetered supply is used for
building work or alterations to existing properties with a
contract value of over £100,000 Thames Water charge
0.17% of contract value, plus VAT and may require
evidence of the contract value.
Where the contract value is less than £100,000 the
property will remain on the current domestic rate of
charge
3.4.2 The new water supply
Thames Water can design and lay the new water main
and communication pipe, from the existing service main
up to the street boundary, for developments within the
City of London.
Understanding the impact that the new development will
have on our network will enable the developer’s team to
plan and budget for any enhancements required.
Using the design Thames Water provide, the developer
may lay the supply pipe from the property to the street
boundary, leaving it uncovered ready for an external
water regulations inspection ensure the design
complies with the Water Supply (Water Fittings)
Regulations 1999.
Thames can be appointed to provide information and
recommend solutions for new developments.
Thames Water new supply contact details
3.4.1 Establishing availability of water capacity at
the proposed development boundary
Seven-day pressure trend
If building a tall property or installing pressure sensitive
fittings, such as combi boilers, then understanding the
pressure in the network will be crucial.
Thames Water provides a seven-day pressure trend to
demonstrate the network pressure in the area adjacent
to the site. This generally take 14days from receipt of a
nominal fee.
Clean water flow and pressure investigation
If planning to develop a large or medium-sized site, or
to build in a pressure-sensitive area, you will need to
know if the existing water network is capable of taking
on the new demand.
Thames Water will undertake flow and pressure
investigation to with details of any enhancements
required to the existing assets.
This takes 14days from receipt of a fee.
Detailed hydraulic model analysis
If the proposed development has more than 1,000 units,
has an industrial use, or is in an area sensitive to water
pressure or sewer flooding, a detailed hydraulic model
analysis to assess the impact on the network is
suggested, this will provide budget cost of any network
enhancements.
An estimate for this service is provided following
payment for a non-refundable deposit.
WATER
For enquiries regarding the self-laying of water mains
and services or any other questions relating to the
building or development work, you can contact Thames
Water on 0845 850 2777 weekdays from 8am to 5pm.
Thames Water Developer Services
Self Lay Unit
PO Box 78
1 Kew Bridge Road
Brentford
Middlesex
TW8 0EF
email:
[email protected]
3.0 NEW CONNECTIONS
3.5 DRAINAGE (THAMES WATER)
Definitions
Public sewer – pipe or structure owned by Thames
Water, conveying the sewerage from two or more
properties.
Lateral drain – pipework between buildings or premises
and the public sewer.
By email
[email protected]
City of London Requirements
If you would like to connect your new or existing property to
our public sewerage system, for both foul water and surface
water (rainwater), you will need to apply for a Section 106
Sewer Connection.
Connection – the operation of joining the lateral drain to
the public sewer
The lateral drain link between the property and the sewer
can be made by your choice of qualified contractors;
however, the City of London must make the connection at
the sewer as above.
The City of London Corporation manages the local sewer
network under contract on behalf of Thames Water. All
applications should be made to the Director of
Environmental Services, Contracts and Drainage
Management Group as below.
The City of London’s Department for environmental services
has a number of requirements that will need to be followed
by the developer governed by the City of London sewers act.
Under section 106 of the Water Industry Act the property
has the right to communicate with a public sewer. Any
new lateral drain to the sewer network will need to be
designed, approved and constructed in accordance with
requirements of both the Building Regulations and the
local bylaws as regulated by the Department of
Environmental Services detailed below.
The drainage system in the City of London is a combined
foul and surface water arrangement, with the two
combining at the point of exit from the property. The
lateral drain shall be constructed in heading by an
experienced contractor employed by the developer at
their expense. The actual connection into the sewer shall
be carried out by the Corporation’s term contractor.
The service provided by the City Of London consists of
the approval of the proposals, inspection of the heading
under the public highway, the connection arrangements,
inspection and approval of the backfilling of the heading,
removal of the bung after testing and the registration of
the connection on behalf of the applicant with Thames
Water. The cost for these actions will be dependant upon
the size of the lateral drain.
Where the heading is wider than 900mm Approval in
Principle will be required for the temporary works under
the highway. the approval will need to be obtained via
the Contracts and Drainage Management Group.
The following guidance is extracted from their standard
requirements.
1.
2.
3.
4.
Notes:
a)
Contact details
By phone
City Of London Contact Centre: 0207 606 3030. Lines
are open weekdays from 8am to 5pm.
By post
Department of Environmental Services
P.O. Box 270
Guildhall
London EC2P 2EJ
DRAINAGE
All lateral drains to the sewer outfall must be
provided with a cast iron intercepting/disconnecting
trap which has a cascade, with access to the crown
of the trap and have rodding access through to the
sewer as BSS figure 26 or equivalent (for rodent
control measures). See sectional detail 2 below.
The lateral drain pipework should be laid in straight
lines in the vertical and the horizontal alignments
and with no other pipe connections. (e g at a self
cleansing velocity and in a straight line from
interceptor to the sewer).
The interceptor should be located inside the
property boundary and adjacent to the buildings
curtilage. There is a requirement for an external
access chamber/ MH for pipes sizes over 375mm.
There should be provision to provide ventilation to
the low invert level of a drainage system this should
normally be at the intercepting trap. It may be
difficult to evaluate air movement precisely and
therefore as guidance you should allow for the vent
pipe to be half diameter at the size of the
intercepting trap. This vent should be discharged to
a safe outlet at roof level atmosphere.
b)
The sewage system within the City historically vents
to atmosphere via low level vents and any increases
of discharge velocity (e.g. pumped drainage) of
building effluent to the sewers results in the
incidences of smells being reported. As justified
smell complaints are treated as a statutory nuisance
by this Department. It is strongly recommended
where practicable and safe to do so all drainage
should discharge via gravity.
In the view of this authority there are rodents present
within the sewers and special rodent control is
3.0 NEW CONNECTIONS
c)
d)
therefore required, historically the measures this
authority accepts is both by means of an
interceptor trap and a sealed drainage system.
You should discuss this matter with your Building
Control body.
There is a requirement under Section 62 of the
Building Act 1984 for any person who carries out
works which result in any part of a drain
becoming permanently disused that they shall
seal the drain at such points as the local authority
may direct. You should therefore make
arrangements to seal off any redundant
communication drains connecting to the Thames
Water Utilities (TWU) sewer at the point of
communication with the local sewer and at the
buildings curtilage.
The City Of London is current asking new
developments when installing new sewer
connections to install a vent pipe from the sewer,
to further vent the sewers and help reduce the
current sewer smells occurring in the streets.
This vent should be discharged to a safe outlet at
roof level atmosphere. See sectional detail 3
below.
Detail 1
DRAINAGE
e)
On new developments, when pumping discharge to
sewers from basements, below the gravity sewer,
a sewer vent should be installed. See sectional
detail 3 below.
Note – These vents should be discharged to a safe outlet at
roof level atmosphere
A failure in respect of these requirements may result in: 1.
2.
3.
Charging of costs and expenses involved in
attending site and auditing works.
Copies of documents concerning any default being
placed on our Land Charges Register and disclosed
to all subsequent enquiries
Charging for remedial works done in default and
costs recovered from responsible person(s) which
may be substantial in terms of cost and delays to the
project.
You are advised to submit proposals in writing, concerning
these matters to the address detailed above.
If you require any further advice or information, City of
London can be contacted on 0207 332 3630 or email
[email protected]
3.0 NEW CONNECTIONS
Detail 2
Detail 3
DRAINAGE
3.0 NEW CONNECTIONS
3.6 ACCOMMODATING FUTURE SERVICES
Decentralised energy generation is likely to become more
commonplace in the future as planning requirements and
building regulations require low carbon energy strategies.
In a decentralised energy scheme electricity is produced
at or near its point of use. Consequently, energy losses
through electricity distribution cables are substantially
reduced. In addition, with a decentralised energy
scheme, potential exists to utilise the thermal energy
produced during the electricity generation process
(normally rejected to atmosphere by traditional power
stations) through the supply of heated and chilled water
to nearby buildings. As a result decentralised energy
schemes are significantly more fuel efficient than
traditional ‘centralised’ energy systems producing far less
carbon dioxide emissions.
A number of buildings within the City of London area are
currently served by the ‘Citigen’ decentralised energy
scheme. These include the historic Guildhall, the
Barbican Arts Centre, the Guildhall School of Music and
Drama, the Museum of London and London Central
Markets (Smithfield). The ‘Citigen’ scheme’s combined
heat and power plant has an electrical output of 25MW
and produces 28MW of heated and chilled water.
Enquiries relating to the possible use of the existing
Citigen system should be made to:
Andrew Crafter
group engineer at the City of London.
[email protected]
0207 3321252.
The City of London has an established network of pipe
subways which already exist below the level where
infrastructure services are normally routed. The existing
pipe subways were constructed between 1869 and 1995
and are currently used to transport gas, electricity, water,
low temperature hot water, chilled water and
telecommunication services. The pipe subways are built
of brick or concrete with access through managed street
level entrance points. Enquiries relating to the possible
use of the pipe subways should be made to the City of
London.
3.6.1 Connecting to a decentralised energy scheme
In a decentralised energy scheme water is circulated
from the heating or cooling source, commonly referred to
as an ‘Energy Centre’, to a building’s ‘substation’ via the
primary pipework distribution network.
Whilst there are a number of pipe materials on the market
in the majority of cases the primary distribution pipework
will be a pre-insulated type comprising of a steel carrier
pipe covered with polyurethane foam insulation and
sealed in a polyethylene outer casing.
The primary distribution pipework connection to the
building may be located within a sub terranian service
FUTURE SERVICES
duct but is more commonly buried directly in the ground as
illustrated in detail below.
The decentralised energy primary distribution pipework may
enter the building from above or below ground from where it
enters or is routed to a plantroom referred to as a
decentralised energy ‘substation’.
Minimum
depth of
500mm
150 – 300 mm between pipes and the
trench walls dependant on pipe size
Typical Pre-insulated pipe trench details
The temperature and pressure of the decentralised
energy primary heating and chilled water supplies are
fixed by the decentralised energy scheme operator and
are likely to be in the following ranges:
Heating
Cooling
Primary
Supply
Temp (oC)
70 - 95
4-8
Primary
Return Temp
(oC)
40 - 65
14
Pressure
(Bar)
3-8
3-8
A decentralised energy scheme’s operating temperature
and pressure must be considered when selecting and
designing a building’s heating, domestic hot water and
cooling services in order to ensure that these secondary
systems can meet their performance requirements.
Typically, the decentralised energy scheme operator will
install, own and maintain the primary distribution pipes
inside the building up to the consumer’s substation.
3.6.2 Decentralised energy scheme substations
Ideally, the decentralised energy scheme operator
should be consulted regarding the location of a
building’s substation plant room as this may be
influenced by the proximity of the existing decentralised
energy primary pipework. As a rule the substation plant
room should be located adjacent to an external wall to
avoid lengthy runs of primary pipework within the
building. A substation may be located in each building
served by the decentralised energy scheme or in some
cases a group of buildings may be served by one
substation.
3.0 NEW CONNECTIONS
The decentralised energy scheme may be connected
either directly or indirectly to a building’s heating or
cooling systems. In the UK it is more common to employ
an indirect connection using heat exchangers located
within the substation as the secondary systems are not
always compatible with the decentralised energy
schemes operating temperatures or pressures. Where
this is the case the heat exchangers provide hydraulic
separation between the decentralised energy scheme’s
primary pipework and the building’s secondary systems.
The dimensions of a decentralised energy substation
plant room are dependant on the thermal energy
demands of the building or buildings served by the
substation. The key components of the substation
plantroom generally include:
1. Shut-off valves on the primary distribution
pipework
2. Controls to regulate flow required to meet the
building’s energy demand and maintain the
decentralised
energy
scheme’s
return
temperatures.
3. Energy (heat) meters.
4. Separate heat exchangers for domestic hot
water, space heating and space cooling.
These key components may be supplied as a
prefabricated packaged unit as illustrated in image below
or supplied as separate items and connected together on
site.
Prefabricated packaged substation
FUTURE SERVICES
4.0 COORDINATION
4.1 BEST PRACTICE
The below HAUCA diagram is the ideal spacing of
services within a pavement. Where these minimum space
requirements cannot be achieved because of physical
footpath constraints alternatives should be negotiated
directly with the utility organisations involved.
4.0 COORDINATION
4.2 TYPICAL BUILDING CONNECTION
ARRANGEMENT
Primary telecom intake typically
150mm DIA hole for 100mm duct
JRF 104 type telecom chamber
Secondary telecom intake
typically 150mm DIA hole for
100mm duct
Fire safety water supply
SECTION A-A
Private
connection
into public
sewer under
carriageway
Sleeved and sealed hole for
future LV / HV intake for life
safety or alternative supply
HV ring main
Combined sewer outlet via
buildings foul and surface
water and disconnecting
trap.
Potable water intake
Multiple telecom
operator in trench share
Gas intake
2No. Capped and sleeved
intake positions typically
200mm for future Bio Fuel
or district heating
connection
Alternative / Diverse
routed telecom intake
position
SECTION B-B
4.0 COORDINATION
SECTION A - A
LV cabling and
street furniture
Un-metered
fire safety
water supply
isolation
chamber
Telecom
trench share
Gas supply
SECTION B - B
Metered water
supply connection
chamber
LV cabling and
street furniture
HV cabling
Gas supply
Telecom
trench share
Combined drainage
sewer connection
4.0 COORDINATION
4.3
the highway by promoting initiatives such as trench
sharing and the deployment of spare ducts nests.
Incoming utility good practice planning
Early programming and coordination of service
connections is paramount in ensuring supplies are
installed and operational for the developments on time
and on budget.
For further enquiries regarding street works coordination
in the City of London please send an e-mail to
[email protected]
Very often the actual location points will be dictated by
the available space within a footpath to make the
connection. Determining these locations should include
where ever trial pit excavations of the existing footpath
to ascertain available space to make a connection or
place a chamber. The primary roads are usually more
congested with larger services and street furniture.
When planning the buildings intake positions it is
recommended where ever possible service intake
positions are on an elevations not on a primary roads.
As indicated in the diagram below.
4.3.2 City of London Considerate Contractor’s
Scheme
The Considerate Contractor Scheme is designed to
create a safer and cleaner environment for all those who
use the highways on a daily basis.
Sites are judged on four basic criteria. Cleanliness,
consideration, co-operation and care, with annual
awards presented to those companies that achieve the
standards set in the Code of Practice.
Open trenches attract fees, early planning and
coordination of services can keep dangerous
excavations to a minimum, reduce program and costs.
4.3.1
For more information on the City’s Considerate
Contractor Scheme please send an e-mail to:
Street works coordination
[email protected]
The Highways Division of the Environmental Services
department at the City of London work closely with
utilities in trying to minimise the disruption of works on
Electrical
intake room
(ring main)
M
SIDE STREET
Gas intake
room
Telecom
intake
Alternative
telecom intake
position
PRIMARY ROAD
4.0 COORDINATION
4.4 BUILDING INTERNAL / BASEMENT UTILITY
SERVICE LAYOUT
When planning utility connections and the associated
internal plant layout consideration should also be given
for future connections for either the current or future
tenants these could include:
ƒ
Alternative Telecom intake
segregation for divers routing.
positions
with
ƒ
Alternative Electrical intake position
segregation distance from existing
with
Alternative fuel
intake position
HV intake and
transformer
room
ƒ
CHP hot water.
ƒ
District heating / cooling
SIDE STREET
Alternative fuel
loading or waste
collection point
Gas meter
room
Primary
telecom
intake frame
room
Heat generation plant
room
Building
riser A
Alternative
LV electrical
intake
position
Secondary
telecom
intake frame
room
Building
riser B
4.0 COORDINATION
4.5 SERVICE ENTRY DETAILS
It is recommended that all building entries are sealed
against both gas and water ingress where under street
level. With the varying water table in the city region,
sealing should be rated to withstand water pressure to
150mm above the external carriageway surface level.
A number of proprietary systems available are suitable
for this application. The type used will depend on the
building construction.
Non membrane service duct entry
Membrane protected service duct entry
5.0 COORDINATION
REFERENCE DOCUMENTS
4.0
ƒ
NJUG Guidelines on the Positioning of
Underground Apparatus for New Development
ƒ
NJUG Guidelines on the Positioning and Colour
Coding of Underground Utilities’ Apparatus
ƒ
NJUG Guidelines for the planning, installation and
maintenance of Utility services in proximity to
trees.
ƒ
Highways Authorities & Utilities
Practical Guide to Street Works
ƒ
BS 6400 – 1, BS 6400 – 2, BS 6700 2006
ƒ
British Telecommunications plc LN 550 Issue 2
ƒ
TGN(T)43 General Requirements for the
installation of Optical Cable in Protective ducts
ƒ
City of London Strategic flood risk assessment
http://www.cityoflondon.gov.uk/Corporation/LGNL
_Services/Environment_and_planning/Planning/L
ocal_Development_Framework/core_strategy_su
st_app.htm
ƒ
The City's Street Scene Manual which outlines the
standards required for City streets is at:
http://www.cityoflondon.gov.uk/Corporation/LGNL
_Services/Environment_and_planning/Urban_desi
gn/Urban+design+publications.htm
ƒ
BT newsite build pack:
http://www.openreach.co.uk/orpg/networkinfo/dow
nloads/newsitesfinal.pdf
ƒ
City of London Archaeology information
Committee:
http://www.cityoflondon.gov.uk/Corporation/LGNL
_Services/Environment_and_planning/Archaeolog
y/Archaeology-local_information.htm
6.0 COORDINATION
PLANNING CONSIDERATIONS
4.0
6.1 PLANNING CONSIDERATIONS
If any development work necessitates alterations to the
external fabric of the building or affects the fabric of a
listed building or Scheduled Ancient Monument, the
developer should confirm whether the works require
planning permission, listed building consent or scheduled
monument consent.
The Department of Planning & Transportation at the City
of London, will provide advice in respect of planning
matters, including listed buildings, monuments and where
any ground works are proposed as these may affect
archaeological remains.
The City of London Corporation’s Planning &
Transportation department can be contacted by sending
an e-mail to:
[email protected]
6.2 TREES, PARKS, GARDENS & OPEN SPACES
Trees, parks, gardens and open spaces are an essential
part of London’s character and identity, and their presence
in the Square Mile is more important than ever. The City
of London is responsible both as an owner and a local
planning authority for maintaining the existing tree
population, and to ensure continuity of trees for the
enjoyment of future generations.
Where works affect street trees or are close to street
trees, the Open Spaces Department should be contacted
prior to commencement of any works. Some trees have
Tree Preservation Orders (TPO’s) or are protected due to
their location within a conservation area. Others may be
subject to planning conditions or be at risk from
redevelopment works. For details of such trees and
advice concerning works which may affect them, the
Department of Planning & Transportation should be
contacted.
All works must adhere to the City of London’s Tree
Strategy, relevant guidance and legislation. Any trees in
the vicinity of a development site should be adequately
protected and works, including the removal of roots,
should not be undertaken until the relevant consents have
been obtained. In addition to complying with any planning
requirements, all works to any trees must adhere to the
"City of London’s Tree Strategy."
The Open Spaces department at the City of London
Corporation can be contacted by sending an e-mail to:
[email protected]
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